Coughing kids may be banished

Some health experts are urging that more children with whooping cough be excluded from schools and early-childhood centres in a bid to combat a rising epidemic.

But the value of quarantining patients at home is doubtful because many cases are not diagnosed in the early, most-infectious stages.

The disease poses the greatest risk to babies and infants, who can suffer breathing problems, pneumonia and, in a few cases, even brain damage or death.

Whooping cough epidemics occur every four to five years in New Zealand. The last was from 1999 to 2001. It peaked in 2000, when 4140 cases were notified.

In the first 10 months of this year, 2330 cases were notified, compared with 457 in the same period last year.

Southland is the hardest-hit area, with a rate of 430 notified cases for every 100,000 people in October, followed by Nelson-Marlborough on 280 and Waikato on 112. Possibly less than a quarter of cases are notified to authorities.

The Institute of Environmental Science and Research says sending home people with whooping cough might be the best tactic, as the vaccine is effective in at most 88 per cent of recipients and since immunity appears to wane within five years.

"Mathematical modelling suggests that the effective vaccination rate may in some cases be as low as 33 per cent," ESR says in its Public Health Surveillance Report for this month.

"Despite the intervention difficulties, control of infectious spread might most usefully, in the short term, be approached through the isolation of infectious cases."

This would mean excluding infected people from early childhood centres, schools and community gatherings "until they are well or have received a recommended course of antibiotics".

Dr Marguerite Dalton, medical adviser to the Immunisation Advisory Centre at Auckland University, said yesterday that children with whooping cough should be kept home while infectious, but this was hard to police.

The difficulty was that the most-infectious period preceded the cough and occurred when the symptoms mimicked a common cold. But all children should be kept home anyway if they had cold symptoms and a fever.

Dr Dalton admitted the vaccine was "not one of the best we have".

 

Dr Alison Roberts, acting manager of the Health Ministry's national immunisation programme, said the ministry recommended that medical officers of health exclude children from school if they were infectious with whooping cough.

"However, in certain cases they may not always follow up and do that, either because of the number of cases or other reasons."

Making greater use of exclusion might help, but not much, "because they are infectious before diagnosis".

Dr Will Paterson, a medical officer of health at Auckland Regional Public Health, said diagnosed children who had taken antibiotics for five days were allowed to return to their school or early-childhood centre. Without antibiotics, they would be allowed back three weeks after coughing started.

But he said exclusion created a false impression of security. Whooping cough would never be eradicated so the best protection was to ensure that those at greatest risk, babies and infants, were vaccinated.

 

WHOOPING COUGH

Incubation period, from infection with droplets to start of symptoms, is from one to three weeks.

Caused by a bacterium, its first symptoms are like a cold: runny nose, sneezing and feeling unwell.

A week or two later comes the characteristic cough: repeated bouts of uncontrolled coughing that end, in many children and babies, with a long, high-pitched inhalation, the "whoop".

The coughing fits gradually subside after several weeks, but a persistent cough can linger for months.

Doctors suspect the disease after at least two weeks of the coughing fits.

Antibiotics do not help individual patients, but stop them being infectious.